1. Field of the Invention
This invention relates to improved aqueous liquid laundry detergent compositions.
2. Background Information Including Description of Related Art
Laundry detergent compositions are sold as either solid, i.e., powder or granular compositions, or liquid compositions. The advantages of liquid over solid compositions are that the caking tending to occur with solid compositions is avoided, the liquid composition is more easily dispersed in wash water, and a liquid is more easily measured and added to the washing machine without spillage than is a solid composition. However, while the cleaning ability of liquid detergents is generally satisfactory, there exist circumstances under which even better cleaning performance would be advantageous. Thus, any expedient which results in a liquid detergent composition having such improved cleaning performance is very desirable.
U.S. Pat. No. 5,004,557, issued Apr. 2, 1991 to Nagarajan et al., teaches aqueous liquid laundry detergent compositions comprising a surfactant, a water-soluble sequester builder, and 0.1 to 2% of a homopolymer or copolymer of acrylic acid having a molecular weight in excess of 100,000 as an anti-redeposition and viscosity control agent. The surfactant may be anionic such as an alkylbenzenesulfonate, nonionic such as a condensation product of ethylene oxide with a C.sub.8 -C.sub.18 primary or secondary aliphatic alcohol, amphoteric such as an N-alkylamino acid, or a combination of such surfactants.
U.S. Pat. No. 5,308,530, issued May 3, 1994 to Aronson et al., discloses a liquid detergent composition comprising a surfactant which may be anionic, nonionic, cationic, zwitterionic or ampholytic, or any combination thereof; a calcium-stabilized enzyme; and as a builder or anti-redeposition agent, a copolymer of an unsaturated carboxylic acid and a hydrophobic monomer prepared by solution polymerization.